Cancer-related fatigue (CRF) is a common experience for children with cancer, yet often under-recognized and under-treated. This is partly due to the lack of appropriate assessments. An appropriate assessment can provide repeated, comprehensive, and precise measurement. These can be easily integrated into clinical practice. Scores can also be compared across age groups and populations. This study aims to develop a clinically-relevant, comprehensive, and methodologically sound fatigue item bank for children with cancer. We expect to achieve this aim through the completion of three "projects". Project 1 is to generate a pediatric cancer-related fatigue question pool, which will be completed via literature review, research and clinical input. Project 2 is to explore patterns of self-reported fatigue using a 'patient as expert' approach (Q-methodology). Project 3 is to develop the proposed item bank by examining dimensionality of items and calibrating their locations onto a common matrix by using both factor analysis and an Itet Response Theory model. At the completion of this study, the bank will include common items appropriate for ages 8-18. Scaling items from different age groups onto a common metric yet taking into account the context of the subjective experience of each age group, this bank can be used to monitor fatigue status longitudinally and therefore, study even the late effects of treatment/disease.